This invention relates to the art of thermostats and, more particularly, to a programmable thermostat system incorporating an integrated liquid crystal display/touch pad unit, constituting a touch screen, for interactive intuitive interface with a user to facilitate programming the thermostat system.
Thermostats have been used for many years as a temperature sensitive switch which controls heating and/or cooling equipment for conditioning a space in which the thermostat, or a temperature sensor connected to the thermostat, is placed. In the well known manner, a simple thermostat can be adjusted to establish a temperature set point such that, when the temperature in the conditioned space reaches the set point, the thermostat interacts with the heating and/or/cooling equipment to take suitable action to heat or cool the conditioned space as may be appropriate for the season.
Modern thermostat systems, which take advantage of the ongoing rapid advances in electronic technology and circuit integration, have many features which provide more precise supervision of the heating and/or cooling equipment to achieve more economical and more comfortable management of the temperature of a conditioned space. Many modem thermostat systems include a real time clock, a memory and a data processor to run a process control program stored in the memory to accurately measure the temperature of a temperature sensor disposed in the conditioned space and to send control signals to the heating and/or cooling equipment to closely control the temperature of the conditioned space. The use of programmed thermostat systems permit anticipating and minimizing hysterisis or overshoot of the temperature in the conditioned space. In addition, the program can specify different set points at different times of the day and week and may also include a xe2x80x9cvacationxe2x80x9d mode which employs different set points when the conditioned space is not occupied for an extended period.
Many modern thermostat systems are programmable by a user. Typically, prior art programmable thermostat system employ a tactile touch pad with various fixed positionbuttons to be touched in a precise sequence to program set points (which may vary with the day of the week) for programmable time periods which may include a vacation mode. The programming sequence may be followed on a separate display, typically a liquid crystal display.
There is a fundamental problem with the prior art programmable thermostat systems: they are difficult to program and some users are unable to successfully program them. This is because the user interfaces which have been employed in prior art programmable interfaces are not highly intuitive. Programmable thermostat systems have incorporated fixed position buttons, at least some of which have multi-functions depending upon the point at which a user has reached in the programming process. The user must usually refer to and attempt to decipher a programming manual (which is often difficult for the average user to readily understand) as the programming proceeds. But, the programming process is so complex to follow while trying to remember the instructions that many users give up, and the full capabilities of the thermostat system cannot be utilized.
The present invention addresses this problem fundamentally and solves the problem in an efficient and highly effective manner.
A programmable thermostat system for controlling space conditioning equipment according to the invention includes: a transparent touch pad juxtaposed over a liquid crystal display to constitute a touch screen for interactive interface with a user; a temperature sensor for providing an electrical signal indicative of the temperature of a conditioned space; and a processor including: a central processing unit; a real time clock; a memory coupled to the central processing unit for storing program and data information; and an input/output unit coupled between the processor and said touch screen for carrying out information transfer therebetween. A program stored in the memory directs the central processing unit to communicate through the input/output unit to selectively: establish on the liquid crystal display a representation of at least one button at a predetermined XY position; read the same XY position on the touch pad to determine if the xe2x80x9cbuttonxe2x80x9d has been touched; and if the button has been touched, perform a predetermined action such as moving to a different menu or changing operating criteria. Preferably, an alphanumeric message explaining the function of the button is also displayed, and icon indicators may be employed to unmistakably associate a message with a button. Different menus can place the buttons and messages in various positions on the touch screen to facilitate intuitive programming.